Stewart's No.20 Home Depot Chevrolet beat Kenseth's Ford by 1.727 seconds.
It was Stewart's first victory of the season and the 30th of his Nextel Cup career.
"The Home Depot guys (pit crew) won us the race today," said Stewart. "They got us the track position we needed ... . Being out front, being in clean air was everything."
Susan Sarandon 'very excited' about daughter's pregnancy
Interpol investigating stolen passports on missing flight